Influence And Analysis Of Stability Between Steep Slope And Bridge Pile Foundation

Compared with the ordinary bridge on the plain,the double pile bridge on the steep slope is very different from the way of Loading mechanism and Stress condition.The lateral load of the soil on the steep slope and the combined load of the pile top acted on the pile,At the same time,the resistance of the pile to the soil and rock mass,thus forming a complex steep slope soil pile interaction system.In this paper,based on the science and technology project of Jiangxi Provincial Department of transportation(Code: 2016C0006),the stability of the double pile column bridge and the buckling stability of the pile are studied.(1)For the homogeneous rock and soil mass in steep slope section,a calculation model of steep slope rock soil and double column pier and beam is constructed,The stress analysis model to draw the energy of the system,and based on the theory of minimum energy can be obtained from sliding soil displacement to be stable after the virtual displacement,in order to calculate the safety factor for slope stability evaluation.In the total potential energy of the system,this paper focuses on the strain energy and the energy of pile and soil friction.The results show that the results of this paper are slightly larger than those of the same type of slope safety factor,The results show that the double column pier is beneficial to the safety of steep slope.In the sensitivity analysis of the safety coefficient of slope,showed little effect on the safety factor of the increase of elastic modulus;pile diameter increases,the area of pile-soil interaction leads to increased,the safety factor is increased;the pile is arranged on the top to the lame horizontal distance position when the half maximum safety coefficient,this position is arranged on both sides of the safety coefficient reduces gradually;steep slope soil cohesion and the internal friction angle increases,slope safety coefficient increasing.(2)The critical slip surface is determined by the improved genetic algorithm.The most dangerous slip surface is composed of five parameters and the safety factor is taken as the objective function,Complete the slip surface search.In order to avoid the local optimal solution,this paper uses the optimized genetic algorithm,In other words,by adding niche technology,the local optimal solution can be avoided to ensure the reliability of the search results.The results show that the parameters have little influence on the shape of the slip surface by changing the parameters within the set range.(3)The problem of buckling stability of bridge piles in steep slope section,Based on the model of the sliding surface and the pile,the length of the different load type is determined,and the energy of the system is calculated according to the stress of each section,Based on the energy method,the characteristic roots of the characteristic equation can be changed,and a method to judge the buckling stability of pile body is obtained.Based on the study of buckling stability of pile body,it is found that the length of embedded section increases and the critical load increases;When the length of the free section of the pile is too long and the pile diameter is too small,The buckling failure of the pile is very easy to occur.